Previously known retaining hooks for blocking a retained position for different scaffold elements at a scaffold normally consists of a hook with a bolt that is displaceable between a blocking position and a releasing position. It must then be verified that the bolt is retained in a blocking position without risk for an unintentional shift. For this purpose, the bolt has to be mounted with well balanced friction or be equipped with a safety lock. Previously known solutions have been relatively expensive, since small tolerances are required and sometimes several movable arts.